Maybe this is an apples vs. oranges answer, or maybe just comparing 2 different kinds of apples, but we’re in Italy right now, halfway thru a 5 week trip. Although we flew American Airlines (say that’s an apple), and not Delta (an orange, or a different apple species???), American had us load all our data - vaccination record, digital Italian Passenger Locator form, and pre-flight negative test into the VeriFLY app. With their access to VeriFLY, American had all our qualifications on file, via VeriFLY, before we ever got to the airport to fly to Italy.
Does Delta have an app, or are they expecting you to show up with paper or separate electronic copies of everything? Abbott Binax gives you an e-mail with your test results. They’re a mainstream test source, and if they’re not the leader in pre-flight tests for Americans, they must certainly be among the trusted test sources. My CDC pass (I’ve called it my “white pass” every time I’m asked by an Italian to show my Green Pass has been universally accepted. With a legitimate negative test, Delta must be as accepting of your test results as Italy has been of the CDC card. Delta just has to accept your Binax results, they just have to. No worries- have a great trip.